Power management is a critical issue for sensing nodes in a sensor network. Since many sensing nodes are powered by batteries, it is apparent that for every function they perform their energy supply decreases. With potentially hundreds to tens of thousands of sensing nodes in a sensor network changing batteries of sensing nodes or refreshing rechargeable batteries can pose a difficult challenge. As such, sensing nodes typically use one or more techniques to mitigate this problem.
One such technique is to connect sensing nodes to regular electrical outlets using power plugs However, it is often impractical for sensor networks with a large number of sensors to be plugged into regular electrical outlets. Not only does it restrict sensor placement, it limits use of existing outlets by other equipment. Furthermore, dedicated wiring adds significant cost and may simply be impractical or undesirably expensive for retrofitting extensive sensor networks in existing buildings.
Another technique is the use of low power sensors and sophisticated power management processes to limit use of battery power, in which sensing nodes are configured to utilize very little power during their off duty cycles. Similar power management techniques try to keep the power draw as low as possible, such that the sensing nodes are sensing for only a small fraction of the time. However for sensing nodes that must run for the majority of the time or for high performance sensing nodes, this technique does not help because the battery power of a sensing node may only last for a matter of hours before it runs out. Furthermore, sensing nodes are used at less than full capabilities solely because of power limitations
Another technique is energy scavenging, which may include e.g. RF induction or the use of solar power. Although the addition of solar energy puts less strain on batteries of sensing nodes, there must be sufficient light to enable the device to be powered device at all times when required. This limitation puts restrictions on the placement of the sensing node, which could potentially affect sensor network performance.
Accordingly, there is a need for a system and method that can allow for more effective power management of sensing nodes in a sensor network.